An Inconvenient Truth
Al Gore’s presentation on global warming is filled with graphs — Gore is fanatical about collecting evidence, even at one point going to the North Pole to persuade the scientists there to release their records of the ice shelves — but only one of them really matters. It comes early in the film, as Gore talks about the large ice core samples that scientists take to trace the history of the Earth’s temperature and CO2 ratings.
Gore shows the results of these samples and then says we can go back further. The screen expands in both directions to show a massive graph of CO2 concentration going back 600,000 years. Its had its fluctuations over that time — large hills and then valleys. Underneath it, he then graphs temperature over the same period.
Temperature tracks CO2 almost exactly, with a several-decade lag. Those large fluctuations? Those were the six ice ages we’ve had over the past 600,000 years. CO2 in the atmosphere goes up and so does the temperature, the CO2 trapping the sun’s radiation inside our planet, where it heats the Earth.
These huge fluctuations are the difference between ice ages and where we are today. Then Gore shows the most recent trajectory of CO2: straight up, more than doubled. “If that much CO2 in one direction causes an ice age,” Gore says, “imagine what it will do in the other direction.” And then he shows the projections for the next 50 years. Again straight up, another doubling. “This is literally off he charts,” he explains. He has to climb up to reach that peak.
“Not a single number in this graph,” he says, “is in dispute.” This is the inconvenient truth: unless we change, we will destroy the environment that sustains our species.
You should follow me on twitterhere.
June 6, 2006